I caught part of a show yesterday, don't remember what channel or what the name was. I think it was a PBS type show. Had a biologist from the NE Aquarium and the lead actor from MASH (forget his name). I know itrs a series, I've seen it before.

Anyway, it caught my eye because the show was about fisheries management in the North East. Part about salmon, part about Bluefin. I caught the Bluefin part. They talked about satalite pop up tag data and how the Biologists from both sides of the Atlantic and Med are tagging giants for migration data. Anyway, there was some information that I thought was interesting so I'll pass it along... (doesn't mean I buy 100% of it, just thought it was interesting).

There are 2 major tagging efforts on the east coast. Stanford University tags out of NC, and NE aquarium biologists out of Gloucester and the GOM. There are also a few over in Europe. For a while people thought the breeding grounds were the Med and Gulf. That the two stocks mixed, but not all that much and a theoretical divide line down the middle of the atlantic separated the two.

Tag data suggests that the two stocks mix frequently and have no dominant route. Giants that one year bred down in the gulf, could go to the med the following year. Or just hang out in the atlantic and not breed at all. Which they thought suggests that giants may take a break from breeding, or there may be alternate breeding areas outside of the known 2 in the mid atlantic.

Also, in the GOM they found giants spend on average 10% of their day on the surface. One of the sources of stock count and estimates come from spotter planes taking photographs. Biologists collect and count the individual surface fish in those photos. On one day in particular (who knows this could have been a banner day) they counted 18,000 giants from photographs of surface schools. So if you pair this with the 10% on the surface logic you can do the math but they are trying to compare this with pop up data and determine if those are realistic assumptions. But, they did say that "scientists" (didn't say which scientists) believe that stock #'s are much higher than previously assumed.

I personaly am not sure if I shoudl think"hmm, thats a lot of giants, thats good news "or "damn, 180,000, thats nothing!" Given hook and line reviews over the past couple years I'm inclined to think the later so I am not so sure what they are excited about.

They also said that the average fish travels 24-30 miles a day making it difficult to rely on visual data.

One piece of information that I thought was most interesting was that when mentioning the mixing of stocks and how surprised they were that so many fish move from coast to coast that this causes serious problems for federal regulators. Quotas set in Europe are much higher, multiples of the US quotas because they are political and tradition driven and not science driven (sound familiar?). That the efforts the US makes to manage the harvest here are being exploited accross the pond by countries with significantly higher quotas.

Pair trawlers were the major source of tagging data. Not because they harvested tagged fish, but because they were most willing to release fish to be tagged and supported more than half of this particular biologist's data. Voluntarily, not mandated. Whether you buy it or not, I thought it was interesting information.

Eddy Merckx

10-31-2005, 10:46 AM

Maybe "Scientific American" on PBS? Alan Alda hosts that show.

ruge13

10-31-2005, 10:48 AM

Yeah, thats ringing a bell. I'm pretty sure thats what it was.

DRYFLY

10-31-2005, 02:27 PM

ruge get yourself a copy of giant bluefin by douglas whynott- i've seen the show before and this book is much more of the info presented here and also lots of great stories of the gulf of maine harpoon (and seine) fishery